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The Single UNIX &reg; Specification, Version 2<br>
Copyright &copy; 1997 The Open Group

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<h4><a name = "tag_001_014_2239">&nbsp;</a>NAME</h4><blockquote>
tee - duplicate standard input
</blockquote><h4><a name = "tag_001_014_2240">&nbsp;</a>SYNOPSIS</h4><blockquote>
<pre><code>

tee <b>[</b>-ai<b>][</b><i>file</i>...<b>]</b>
</code>
</pre>
</blockquote><h4><a name = "tag_001_014_2241">&nbsp;</a>DESCRIPTION</h4><blockquote>
The
<i>tee</i>
utility will copy standard input to standard output,
making a copy in zero or more files.
The
<i>tee</i>
utility will not buffer output.
<p>
The options determine if the specified files are overwritten
or appended to.
</blockquote><h4><a name = "tag_001_014_2242">&nbsp;</a>OPTIONS</h4><blockquote>
The
<i>tee</i>
utility supports the <b>XBD</b> specification, <a href="../xbd/utilconv.html#usg"><b>Utility Syntax Guidelines</b>&nbsp;</a> .
<p>
The following options are supported:
<dl compact>

<dt><b>-a&nbsp;</b>
<dd>
<dt><b>-a&nbsp;</b><i>(null)</i>
<dd>Append the output to the files rather than overwriting them.

<dt><b>-i&nbsp;</b>
<dd>
<dt><b>-i&nbsp;</b><i>(null)</i>
<dd>Ignore the SIGINT signal.

</dl>
</blockquote><h4><a name = "tag_001_014_2243">&nbsp;</a>OPERANDS</h4><blockquote>
The following operands are supported:
<dl compact>

<dt><i>file</i><dd>A pathname of an output file.
Processing of at least 13
<i>file</i>
operands will be supported.

</dl>
</blockquote><h4><a name = "tag_001_014_2244">&nbsp;</a>STDIN</h4><blockquote>
The standard input can be of any type.
</blockquote><h4><a name = "tag_001_014_2245">&nbsp;</a>INPUT FILES</h4><blockquote>
None.
</blockquote><h4><a name = "tag_001_014_2246">&nbsp;</a>ENVIRONMENT VARIABLES</h4><blockquote>
The following environment variables affect the execution of
<i>tee</i>:
<dl compact>

<dt><i>LANG</i><dd>Provide a default value for the internationalisation variables
that are unset or null.
If
<i>LANG</i>
is unset or null, the corresponding value from the
implementation-dependent default locale will be used.
If any of the internationalisation variables contains an invalid setting, the
utility will behave as if none of the variables had been defined.

<dt><i>LC_ALL</i><dd>
If set to a non-empty string value,
override the values of all the other internationalisation variables.

<dt><i>LC_CTYPE</i><dd>
Determine the
locale for the interpretation of sequences of bytes of text data as
characters (for example, single- as opposed to multi-byte characters
in arguments).

<dt><i>LC_MESSAGES</i><dd>
Determine the locale that should be used to affect
the format and contents of diagnostic
messages written to standard error.

<dt><i>NLSPATH</i><dd>
Determine the location of message catalogues
for the processing of
<i>LC_MESSAGES .
</i>
</dl>
</blockquote><h4><a name = "tag_001_014_2247">&nbsp;</a>ASYNCHRONOUS EVENTS</h4><blockquote>
Default, except that if the
<b>-i</b>
option was specified, SIGINT will be ignored.
</blockquote><h4><a name = "tag_001_014_2248">&nbsp;</a>STDOUT</h4><blockquote>
The standard output will be a copy of the standard input.
</blockquote><h4><a name = "tag_001_014_2249">&nbsp;</a>STDERR</h4><blockquote>
Used only for diagnostic messages.
</blockquote><h4><a name = "tag_001_014_2250">&nbsp;</a>OUTPUT FILES</h4><blockquote>
If any
<i>file</i>
operands are specified, the standard input will be
copied to each named file.
</blockquote><h4><a name = "tag_001_014_2251">&nbsp;</a>EXTENDED DESCRIPTION</h4><blockquote>
None.
</blockquote><h4><a name = "tag_001_014_2252">&nbsp;</a>EXIT STATUS</h4><blockquote>
The following exit values are returned:
<dl compact>

<dt>0<dd>The standard input was successfully copied to all output files.

<dt>&gt;0<dd>An error occurred.

</dl>
</blockquote><h4><a name = "tag_001_014_2253">&nbsp;</a>CONSEQUENCES OF ERRORS</h4><blockquote>
If a write to any successfully opened
<i>file</i>
operand fails,
writes to other successfully opened
<i>file</i>
operands and standard output will continue,
but the exit status will be non-zero.
Otherwise, the default actions specified in
<a href="utildes.html">Utility Description Defaults</a>
<xref href=utildes></xref>
will apply.
</blockquote><h4><a name = "tag_001_014_2254">&nbsp;</a>APPLICATION USAGE</h4><blockquote>
The
<i>tee</i>
utility is usually used in a pipeline, to make a copy of the
output of some utility.
<p>
The
<i>file</i>
operand is technically optional, but
<i>tee</i>
is no more useful than
<i><a href="cat.html">cat</a></i>
when none is specified.
</blockquote><h4><a name = "tag_001_014_2255">&nbsp;</a>EXAMPLES</h4><blockquote>
Save an unsorted intermediate form of the data in a pipeline:
<pre>
<code>
. . . | tee unsorted | sort > sorted 
</code>
</pre>
</blockquote><h4><a name = "tag_001_014_2256">&nbsp;</a>FUTURE DIRECTIONS</h4><blockquote>
None.
</blockquote><h4><a name = "tag_001_014_2257">&nbsp;</a>SEE ALSO</h4><blockquote>
<i><a href="cat.html">cat</a></i>.
</blockquote><hr size=2 noshade>
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Copyright &copy; 1997 The Open Group
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